The nurse respond should be is "Is he able to sit unsupported?”. The mother in this situation is telling about the rooting reflex; when touched on the cheek, the infant reflexively turns the head to that side. The rooting reflex is likely to disappear by 4 months of age. An infant can sit without support at 8 months; this is not expected of a 5-month-old infant. Stroking the sole of the foot provokes the Babinski reflex, which disappears between 8 and 12 months of age. The disappearance of the rooting reflex at 5 months of age does not require further intervention